weird noise?

[SirDan]

When i push the brake pedal fast it sometimes makes a weird noise. I can feel it a bit in the pedal too. Its not a noise like something is loose. Its like a lower brrummpp kind of noise. Other than that I have my brakes working great.

 

[green1]

Vacuum starting to leak.

 

[SirDan]

Brand new booster, new hose to the booster. I honestly dont think it sounds like a vacuum leak, the idle does not change either when this happens.